Roller support means for roller twisting apparatus

ABSTRACT

A reciprocating roller twisting mechanism including a hollow cylindrical roller supported internally on a pair of bearing members spaced longitudinally thereof, a rod extending from outside the roller through one of said bearing members into the interior of the roller between the bearing members where it is fastened to the roller by fastening means and means to reciprocate the rod longitudinally and simultaneously to rotate it thereby to impart axial reciprocation and simultaneous rotation of the roller on said bearing members.

United States Patent Henshaw et al.

[451 Sept. 26, 1972 [541 ROLLER SUPPORT MEANS FOR ROLLER TWISTING APPARATUS [72] inventors: David Ernest Henshaw, 5 Calbin Avenue, Belmont, Victoria; Lionel Stern, 39 Stawell St., Kew, Victoria, both of Australia [22] Filed: Feb. 9, 197] [21] Appl. No.: "4,018

[30] Foreign Application Priority Data Feb. 9, 1970 Australia ..PA 0284/70 [52] U.S. Cl ..57/77.42, 57/34 AT, 308/5 R [51] Int. Cl. ..D0lh 7/46 [58] Field of Search ..308/5, DIG. l; 57/77.4, 34 AT, 57/77.42; 226/194, 198; 29/126, 127, 128,

[56] References Cited UNITED STATES PATENTS 3,377,792 4/1968 Walls et a1. ..57/77.4

3,160,357 12/1964 Jackson ..308/D1G. l

FOREIGN PATENTS 0R APPLICATIONS 851,139 3/1939 France .308/5 Primary Examiner-Martin P. Schwadron Assistant Examiner-Ronald H. Lazarus Altorney-Sughrue, Rothwell, Mion, Zinn & Macpeak 57 ABSTRACT A reciprocating roller twisting mechanism including a hollow cylindrical roller supported internally on a pair of bearing members spaced longitudinally thereof, a rod extending from outside the roller through one of said bearing members into the interior of the roller between the bearing members where it is fastened to the roller by fastening means and means to reciprocate the rod longitudinally and simultaneously to rotate it thereby to impart axial reciprocation and simultaneous rotation of the roller on said bearing members.

2 Claims, 2 Drawing Figures ROLLER SUPPORT MEANS FOR ROLLER TWISTING APPARATUS BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to reciprocating roller twisting apparatus of the type referred to in our Australian Pat. No. 288,664 and is directed particularly to an improved means for supporting the reciprocating rollers.

2. Description of the Prior Art In the construction and operation of roller twisting mechanisms, it is particularly important that the rollers be accurately positioned and supported and also that disturbance and contamination of the strand being twisted is avoided. For high production rates, it is necessary that the rollers be rotated and reciprocated rapidly. It is thus important to reduce so far as possible the mass to be reciprocated to provide bearings which are capable of handling high speed rotation and reciprocation simultaneously and to eliminate wherever possible sources of bearing play, deflection and vibration. Heating of the rollers must also be minimized as the physical properties of their coatings deteriorate with increasing temperature and any expansion due to heating complicates the adjustment of the gap between the rollers.

SUMMARY With the above objectives in view, there has been produced, according to one aspect of this invention, a reciprocating roller twisting mechanism including a hollow cylindrical roller supported internally on a pair of bearing members spaced longitudinally thereof, a rod extending from outside the roller through one of said bearing members into the interior of the roller between the bearing where it is fastened to the roller by fastening means and means to reciprocate the rod longitudinally and simultaneously to rotate it thereby to impart axial reciprocation and simultaneous rotation of the roller on said bearing members.

Preferably the rod is coaxial with the roller throughout its length.

The invention also provides, according to a further aspect, a reciprocating roller twisting mechanism including a hollow reciprocable and rotatable roller having an internal cylindrical bearing surface, a mandrel supported on a frame and arranged to project into the interior of the roller, a plurality of orifices arranged about the periphery of the mandrel and means to direct gas under pressure through the orifices against the bearing surface to form a gas bearing whereby the roller is supported on the mandrel.

Preferably, the mandrel is hollow and is provided internally with a manifold to supply gas to the orifices and with an exhaust passage to exhaust gas from the interior of the roller. The manifold and the exhaust passage may conveniently be formed by providing a tube located within the mandrel and internally spaced from the walls of the mandrel, to provide around the outside of the tube an annular space which serves as the manifold. Preferably also, there are two mandrels, one entering the roller from one end and the other entering the roller from the other to provide two spaced bearing supports. The reciprocating and rotating drive may be supplied to the roller through a connecting rod passing through the mandrel. Preferably, the connection between the connecting rod and the roller is by means of a resilient connection such as a rubber bush.

BRIEF DESCRIPTION OF THE DRAWINGS In order that the invention may be better understood, a particular construction will now be more fully described with reference to the accompanying drawings wherein FIGS. 1 and 2 are contiguous on the line X-X to form a longitudinal cross-section through one form of construction in accordance with the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in the drawings a hollow roller 1 is mounted on two air bearings 2 formed at the ends of mandrels 3 mounted on frame 4. Each mandrel is hollow and has mounted within it a tube 5 which is expanded at each end 6 to form a closed annular space 7 between the interior of the mandrel and the exterior of the tube. Compressed air is supplied to this space through the passageway 8 and the space therefore forms a manifold supplying the compressed air to the orifices 9 of the bearing 2. The air discharged from the orifices impinges against the interior bearing surface 10 of the roller and discharges from each end of the bearing to atmosphere, either around the outside of the mandrel or through the exhaust passage 11 formed by the interior of the tube 5. Design criteria for the critical parameters of the hearing are established in the prior known art of external type air bearings and may be obtained from standard texts on this subject, for example, Gas Lubricated Bearings" by Grassam and Power (Butterworths 1964). The design criteria for the internal type of air bearing in this construction are the same as for a conventional external type.

The drive connection of the roller is by means of a connecting rod 12 which is connected at its outer end to a rotating and reciprocating drive means (not shown). The inner end of the connecting rod is attached to a connecting piece 13 which is in turn attached to the interior of the roller. The connection between the connecting rod and the connecting piece is by means of a rubber bush 14 which absorbs vibration and compensates for any misalignment between the axis of the connecting rod and the axis of the roller. Connecting piece 13 is perforated by a number of axial holes 16 which allow air to pass through the connecting piece and so reduce to a minimum any pumping action of this part during reciprocation. As will be seen from the drawing, each mandrel and its associated bearing is similarly constructed and air is free to flow unimpeded through the interior of the second mandrel. It will be appreciated also that the twisting mechanism comprises a roller pair between which the strand is twisted. The second roller of the pair is shown partly in outline at 15 in the drawing and this roller is of the same construction and is supported similarly to the roller 1.

Whilst there has been described one particular construction according to this invention, it is to be understood that this construction is exemplary only and the present invention is in no way limited thereto. For example, although in the described construction the pumping action of connecting piece 13 is reduced to a minimum by the provision of holes 16, it would be possible to design the mandrels and connecting piece 13 in such a way that air is trapped so as to cushion the reciprocatory motion at either end of each stroke and to thereby reduce the load on the drive mechanism. This modification may not normally be preferred because of the concomitant heating involved but may well be worthwhile where high speed reciprocation-in excess of L500 oscillations per minute-is involved and where, for example, it may be worthwhile to cool the air or take other steps to keep the temperature rise within satisfactory limits. The tubular connecting rod itself may be employed to admit or exhaust air from within the roller and flap or similar valves may be included in the exhaust passages so that air is exhausted from, or circulated through; the rollers by the pumping action. It is to be understood that these and many other modifications and adaptations may be made to the specifically described construction without departing from the scope of the appended claims.

lclaim:

1. Apparatus for twisting a travelling strand to impart to said strand alternating zones of opposite twist, said apparatus comprising a pair of hollow nip rollers; roller support means supporting the rollers for rotation and longitudinal reciprocation; and drive means for simultaneously rotating the rollers and reciprocating them in opposite phase; wherein each roller has ateach end an internal cylindrical bearing surface, said roller support means comprises two pairs of mandrels each pair extending into the opposite ends of each of the rollers within the respective internal cylindrical bearing surfaces, the inner ends of each pair of mandrels within a roller being spaced apart by a distance which is greater than the stroke of the roller reciprocation, a plurality of orifices in each mandrel arranged about the periphery of that mandrel and means to direct gas under pressure through the orifices against the adjacent bearing surface to form a gas bearing supporting the respective roller end on the mandrel, at least one mandrel of each of said pairs of mandrels being hollow to provide a central passage extending through that mandrel to the interior of the respective roller between the respective pair of mandrels; and said drive means comprises a pair of connecting rods each of which extends through the central passage of the said hollow mandrels in each roller and means for securing the inner ends of the connecting rods to the rollers, each of said hollow mandrel having a tube lining the central passage of the mandrel and defining an annular space serving as a supply manifold via which gas is supplied to said orifices of the mandrel.

2. Apparatus as claimed in claim 1, wherein each of said fastener means includes passage means for the flow of gas therethrough longitudinally of the respective roller thereby to reduce any pumping action of the fastener means on reciprocation of the roller. 

1. Apparatus for twisting a travelling strand to impart to said strand alternating zones of opposite twist, said apparatus comprising a pair of hollow nip rollers; roller support means supporting the rollers for rotation and longitudinal reciprocation; and drive means for simultaneously rotating the rollers and reciprocating them in opposite phase; wherein each roller has at each end an internal cylindrical bearing surface, said roller support means comprises two pairs of mandrels each pair extending into the opposite ends of each of the rollers within the respective internal cylindrical bearing surfaces, the inner ends of each pair of mandrels within a roller being spaced apart by a distance which is greater than the stroke of the roller reciprocation, a plurality of orifices in each mandrel arranged about the periphery of that mandrel and means to direct gas under pressure through the orifices against the adjacent bearing surface to form a gas bearing supporting the respective roller end on the mandrel, at least one mandrel of each of said pairs of mandrels being hollow to provide a central passage extending through that mandrel to the interior of the respective roller between the respective pair of mandrels; and said drive means comprises a pair of connecting rods each of which extends through the central passage of the said hollow mandrels in each roller and means for securing the inner ends of the connecting rods to the rollers, each of said hollow mandrel having a tube lining the central passage of the mandrel and defining an annular space serving as a supply manifold via which gas is supplied to said orifices of the mandrel.
 2. Apparatus as claimed in claim 1, wherein each of said fastener means includes passage means for the flow of gas therethrough longitudinally of the respective roller thereby to reduce any pumping action of the fastener means on reciprocation of the roller. 